Prefabricated timber formwork beams - Requirements, classification and assessment

This European Standard specifies classification, requirements and assessment procedures for prefabricated timber formwork beams. It also gives information on production control requirements.
Prefabricated timber formwork beams are intended for use in falsework and formwork and to be loaded in the direction of the beam depth.
They are of glued I-shaped construction consisting of two identical flange members of solid timber connected by a single web of wood based material with beam depths of 160 mm, 200 mm and 240 mm, connected by or a lattice of solid timber members with a beam depth of 240 mm beam depth.

Industriell gefertigte Schalungsträger aus Holz - Anforderungen, Klassifizierung und Nachweis

Diese Europäische Norm gibt die Klassifizierung, die Anforderungen und die Nachweisverfahren für industriell gefertigte Schalungsträger aus Holz an. Sie gibt weiterhin Informationen über die Anforderungen an die Produktionsüberwachung an.
Industriell gefertigte Schalungsträger aus Holz sind für die Verwendung in Traggerüsten und Schalungen vorgesehen und werden in Richtung der Trägerhöhe belastet.
Die Träger haben eine I-förmig verleimte Konstruktion bestehend aus zwei identischen Gurten aus Vollholz, die durch einen Steg aus Holzwerkstoff verbunden sind, mit Trägerhöhen von 160 mm, 200 mm und 240 mm, oder die durch ein Gitter aus Vollholzstreben verbunden sind mit einer Trägerhöhe von 240 mm.

Poutrelles de coffrage préfabriquées en bois - Exigences, classification et évaluation

La présente Norme européenne spécifie la classification, les exigences et les modes opératoires d'évaluation pour les poutrelles de coffrage préfabriquées en bois. Elle fournit également des informations sur les exigences du contrôle de la production.
Les poutrelles de coffrage préfabriquées en bois sont destinées a etre utilisées dans les échafaudages d'étaiement et les coffrages, et a recevoir une charge dans le sens de leur hauteur.
Elles sont collées selon une construction en forme de   se composant de deux ailes identiques de bois dur reliées par une âme en matériau a base de bois avec des hauteurs de poutrelles de 160 mm, 200 mm et 240 mm, ou par un triangle constitué d'éléments en bois dur présentant une hauteur de poutrelle de 240 mm.

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General Information

Status
Published
Publication Date
30-Nov-2002
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
01-Dec-2002
Due Date
01-Dec-2002
Completion Date
01-Dec-2002

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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.]RYDQMHIndustriell gefertigte Schalungsträger aus Holz - Anforderungen, Klassifizierung und NachweisPoutrelles de coffrage préfabriquées en bois - Exigences, classification et évaluationPrefabricated timber formwork beams - Requirements, classification and assessment91.220Gradbena opremaConstruction equipmentICS:Ta slovenski standard je istoveten z:EN 13377:2002SIST EN 13377:2002en01-december-2002SIST EN 13377:2002SLOVENSKI

STANDARD
SIST EN 13377:2002

EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 13377August 2002ICS 91.220English versionPrefabricated timber formwork beams - Requirements,classification and assessmentPoutrelles de coffrage préfabriquées en bois - Exigences,classification et évaluationIndustriell gefertigte Schalungsträger aus Holz -Anforderungen, Klassifizierung und NachweisThis European Standard was approved by CEN on 29 May 2002.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36

B-1050 Brussels© 2002 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 13377:2002 ESIST EN 13377:2002

EN 13377:2002 (E)2ContentspageForeword......................................................................................................................................................................3Introduction.................................................................................................................................................................41Scope..............................................................................................................................................................42Normative references....................................................................................................................................43Terms, definitions and symbols...................................................................................................................54Classification..................................................................................................................................................85Performance requirements...........................................................................................................................86Prototype assessment.................................................................................................................................117Evaluation of conformity.............................................................................................................................118Ongoing production inspection.................................................................................................................129Marking.........................................................................................................................................................1210Instructions for use.....................................................................................................................................12Annex A (normative)

Test and calculation methods to establish structural parameters.................................13Annex B (normative)

Statistical analysis of test results for the calculation of the characteristic value........18Annex C (normative)

Minimum requirements for production control................................................................19Annex D (normative)

Test procedures for beams with webs conforming to 5.2.2.c)........................................21Annex E (informative)

Values for use in calculation for site use........................................................................24Annex F (informative)

Ongoing production inspection........................................................................................26Bibliography..............................................................................................................................................................27SIST EN 13377:2002

EN 13377:2002 (E)3ForewordThis document EN 13377:2002 has been prepared by Technical Committee CEN/TC 53 "Temporary worksequipment", the secretariat of which is held by DIN.This European Standard shall be given the status of a national standard, either by publication of an identical text orby endorsement, at the latest by February 2003, and conflicting national standards shall be withdrawn at the latestby February 2003.The annexes A, B, C and D are normative, the annexes E and F are informative.According to the CEN/CENELEC Internal Regulations, the national standards organizations of the followingcountries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain,Sweden, Switzerland and the United Kingdom.SIST EN 13377:2002

EN 13377:2002 (E)4IntroductionThis European Standard is a product standard primarily for use in the field of falsework and formwork.Formwork beams should be made so that the properties specified in clause 5 are retained under site conditionssuch as exposure to water, water vapour and cement.Whilst this European Standard deals with the two most common types of prefabricated timber formwork beams in useit is not intended to prevent development of other types of formwork beams made of timber and wood basedmaterials.Research and development in the field of panel materials is continuous. Even if formwork beams are made withmaterials which do not conform with this European Standard, the principles of this European Standard should beconsidered in the design and assessment of such beams.To obtain test results and their statistical evaluation annexes A and B respectively can be used. The values forstrength and stiffness given in Tables 1 and 2 have been established from experience. To use these values, thepartial safety factor for actions, gF, should be taken into account as well as the partial safety factor for the material, gM,and modification factor, kmod, for timber, (see ENV 1995-1-1). Annex E gives some guidance. For more information ontimber see the Bibliography in annex F.1 ScopeThis European Standard specifies classification, requirements and assessment procedures for prefabricated timberformwork beams. It also gives information on production control requirements.Prefabricated timber formwork beams are intended for use in falsework and formwork and to be loaded in thedirection of the beam depth.They are of glued I-shaped construction consisting of two identical flange members of solid timber connected by asingle web of wood based material with beam depths of 160 mm, 200 mm and 240 mm, or connected by or a lattice ofsolid timber members with a beam depth of 240 mm beam depth.2 Normative referencesThis European Standard incorporates by dated or undated reference, provisions from other publications. Thesenormative references are cited at the appropriate places in the text, and the publications are listed hereafter. Fordated references, subsequent amendments to or revisions of any of these publications apply to this EuropeanStandard only when incorporated in it by amendment or revision. For undated references the latest edition of thepublication referred to applies (including amendments).EN 301, Adhesives, phenolic and aminoplastic for load bearing timber structures — Classification and performancerequirements.EN 310, Wood-based panels – Determination of modulus of elasticity in bending and of bending strength.EN 317, Particleboards and fibreboards — Determination of swelling in thickness after immersion in water.EN 319, Particleboards and fibreboards — Determination of tensile strength perpendicular to the plane of theboard.EN 323, Wood based panels — Determination of density.SIST EN 13377:2002

EN 13377:2002 (E)5EN 338, Structural timber — Strength classes.EN 385:1995, Finger jointed structural timber — Performance requirements and minimum production requirements.EN 408, Timber structures —Solid timber and glued laminated timber — Determinations of some physical andmechanical properties.EN 518, Structural timber — Grading — Requirements for visual strength grading standards.EN 519, Structural timber — Grading — Requirements for machine strength graded timber and grading machines.EN 636-3, Plywood — Specifications — Part 3: Requirements for plywood for use in exterior conditions.ENV 1995-1-1:1993, EUROCODE 5: Design of timber structures — Part 1-1: General rules and rules for buildings.EN 13183-2, Moisture content of a piece of sawn timber - Part 2: Estimation by electrical resistance method.prEN 13353, Solid-wood-panels — Requirements.prEN 13354, Solid-wood-panels — Bonding quality — Test method.3 Terms, definitions and symbols3.1 Terms and definitionsFor the application of this European Standard, the following terms and definitions apply.3.1.1formwork beambeam in formwork construction and loaded in the direction of the beam depth3.1.2timber formwork beamglued prefabricated I-shaped beam consisting of two identical flange members of solid timber connected by a webof wood based panel material or a lattice of solid timber members3.1.3panel web beamtimber formwork beam in which the web is made of a wood based panel material (see Figure 1a))3.1.4lattice web beamtimber formwork beam made with lattice struts (see Figure 1b)).3.1.5lattice strutmember, positioned diagonally or at right angles to the flange, which connects two parallel flange members (seeFigure 1b))SIST EN 13377:2002

EN 13377:2002 (E)6KeyHDepth of beambFlange widthhDepth (thickness) of flangetThickness of webKey1Flange2Panel web3Vertical strut4Diagonal struta) Panel web beam (type P)b) Lattice web beam (type L)Figure 1 — Timber formwork beamsGeneral construction and symbols used for the dimensions3.2 SymbolsThe principal symbols used in this standard are listed below:SIST EN 13377:2002

EN 13377:2002 (E)7NumberSymbolDenominationUnit1amodule of the lattice web beammm2bflange widthmm3edistance of proportion at load positions4Emodulus of elasticitykN/mm25EIbending stiffnesskNm26FactionkN7Hdepth of beammm8hdepth (thickness) of flangemm9Isecond moment of areamm410kmodmodification factor11ksstatistical factor12Lspan of beamm13Mbending resistancekNm14nnumber of specimens15RresistancekN/mm216sstandard deviation17tthickness of webmm18Vshear resistancekN19Wsection modulusmm320ymean value21yisingle value22gFpartial safety factor for actions23gMpartial safety factor for materialSubscripts24...bbearing25...ddesign level in limit state26...itypical/any value27...kcharacteristic value (limit state)28...m"supported between node points"29...modmodification30...n"supported at node point"31...sstatistical32...uultimate (limit state)33...yvalue related to transformed values34...55 % quantile valueSIST EN 13377:2002

EN 13377:2002 (E)84 ClassificationThis standard specifies types of beam; the classification is based on:¾ the web construction:Type P for a panel web beam;Type L for a lattice web beam;¾ the overall depth, H: the two digits in the identification symbols represent the depth in centimetres.The nominal load bearing and rigidity properties for each class are listed in Tables 1 and 2.For classification see Tables 1 and 2. The identification symbols are given in column 1 of Tables 1 and 2.Table 1 — Classification, dimensions and structural properties of panel web beams1234567Classbeam depthH [mm]minimum flange widthb [mm]EI[kNm2]Vk[kN]Rb,k[kN]Mk[kNm]P161606520018,436,85.9P202008045023,947,810.9P242408070028,256,414.1NOTE 1For explanation of symbols, see 3.2.NOTE 2For calculation of ”safe working loads”, see annex E.Table 2 — Classification, dimensions and structural properties of lattice web beams123456789Rb,n,k[kN]Rb,m,k[kN]Mn,k[kNm]Mm,k[kNm]Classbeamdepth H[mm]minimumflangewidth b[mm]EI[kNm2]Vk[kN]supportedat nodessupportedin betweennodessupportedat nodessupportedin betweennodesL242408080028,260,743,415,28,7NOTE 1For explanation of symbols, see 3.2.NOTE 2For calculation of ”safe working loads”, see annex E.To obtain the required bearing area, the lateral compression strength for the strength class C 24 with 5,3 N/mm²

inaccordance with EN 338:1995 shall be used.5 Performance requirements5.1 GeneralBeams shall conform to the requirements of this clause according to their class. Conformity with the requirementsshall be verified, see clauses 6 and 7, and manufacturing shall be subject to production control, see clause 8 andannex C.SIST EN 13377:2002

EN 13377:2002 (E)9All requirements should be met with a moisture content of solid timber members of (12 ± 2) % (manufacturingtarget moisture content).5.2 Material and assembly requirements5.2.1 Solid timber components – strength classMembers of solid timber shall at least conform to strength class C 24 of EN 338.NOTEIt is recommended that the growth ring width is less than 4 mm and the amount of compression wood does notexceed 20 %.5.2.2 Wood based panel componentsThe web shall be made of one of the following materials:a) plywood conforming to EN 636-3;b) solid wood panels for use in exterior conditions conforming to prEN 13353;c) any other wood based material, which conforms after passing the wet-dry-cyclic test (see annex D) with thesubsequent requirements:i) tension strength perpendicular to the plane determined in accordance with EN 319 shall not be less than0,1 N/mm2 (see D.3.1); andii) irreversible swelling shall not exceed 20 % (see D.3.2).The following properties of this wood based material shall be made available:¾ density established in accordance with EN 323;¾ bending strength established in accordance with EN 310;¾ thickness swelling established in accordance with EN 317;¾ internal bond established in accordance with EN 319.The established properties shall be used as requirements for production control (see annex C).5.2.3 Shear strength of the glue line in beam sections with webs conforming to 5.2.2cAfter applying the wet-dry cyclic testing procedure given in annex D, the mean value of the shear strength of beamsections shall be at least 9 kN (see D.4.6).5.2.4 Glued finger jointsGlued finger joints in flanges shall conform to EN 385.5.2.5 GlueGlue shall fulfil the requirements of type I of EN 301.SIST EN 13377:2002

EN 13377:2002 (E)105.3 Dimensions5.3.1 Principal dimensionsThe length of the beam shall conform to the manufacturers declared dimension within a tolerance of 10 mm.The beam depth, H, shall conform to the data in Tables 1 and 2 within a limit deviation of ± 1 % or ± 2 mm,whichever is the smaller.The flange width, b, shall conform to the data in Tables 1 and 2 and to the manufacturers declared dimension withina limit deviation of + 1 % and – 1,5 %.The web thickness, t, shall conform to the manufacturers declared dimension within a limit deviation of ± 3 %.The lattice dimensions shall conform to the manufacturers declared dimensions within a limit deviation of ± 1,5 %.5.3.2 Dimensional movement due to moisture variationWithin the range of moisture content of 10 % to 20 %, the dimensional movement of depth H shall notexceed 1,0 % of H.5.4 Structural properties5.4.1 GeneralThe characteristic resistances given in 5.4.2 and 5.4.3 are for the 5 % quantile with a 75 % confidence level.5.4.2 Panel web beamThe values of the characteristic ultimate resistance and stiffness of a panel web beam shall be at least as great asthe values given in Table 1 for the relevant class.a) The characteristic ultimate shear resistance, Vk, see column 5.b) The characteristic ultimate bearing resistance, Rb,k, see column 6.c) The characteristic ultimate bending resistance, Mk, see column 7.d) The stiffness, EI, see column 4.5.4.3 Lattice web beamThe values of the characteristic ultimate resistance and stiffness of a lattice beam shall be at least as great as thevalues given in Table 2.a) The characteristic ultimate shear resistance, Vk, see column 5.b) The characteristic ultimate bearing resistance, Rb,n,k, when supported at node points, see column 6.c) The characteristic ultimate bearing resistance, Rb,m,k, when supported between node points, see column 7.d) The characteristic ultimate bending resistance, Mn,k, when is supported at node points, see column 8.e) The characteristic ultimate bending resistance, Mm,k, when supported between node points, see column 9.f) The stiffness, EI, see column 4.SIST EN 13377:2002

EN 13377:2002 (E)116 Prototype assessmentFor each model of beam a sample of prototype beams shall be assessed. For this purpose, a model of beam is ofone construction but of any length. The model of beam shall conform to the requirements of clauses 5 and 10 ofthis standard and the manufacturer’s specifications.7 Evaluation of conformity7.1 GeneralEvaluation of the model of beam shall verify conformity to the relevant requirements of this standard.7.2 Process of assessment7.2.1For the prototype beams the following shall be made available by the manufacturer:¾ class of beam;¾ product drawings;¾ specification (standard, grade or type) of materials;¾ specification of the glue;¾ required testing sample of components and beams for tests of web material to evaluate conformity withrequirements of 5.2.2.c and 5.3, if web material according 5.2.2.c is used;¾ required testing sample of prototype beams for tests to evaluate conformity with requirements of 5.4.7.2.2It shall be verified that the prototype beams conform to the requirements of 5.2.Beams with web materials in accordance with 5.2.2.c shall be tested as specified in annex D. Test results shallconform to the requirements of 5.2.2.c and 5.2.3.7.2.3It shall be verified that the prototype beams conform to the requirements of 5.3.7.2.4Verification of the structural properties specified in 5.4 shall be by testing in accordance with A.1 and A.2and calculation in accordance with A.3.7.2.5For each test specified in A.2 and for tests at each of the stages given in annex D, a minimum number of10 tests on specimens chosen from a batch of 50 beams is required. Specimens chosen shall have glued fingerjoints in one or both flanges and in the web in accordance with Figures A.1 and A.2.7.2.6Characteristic res

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